In general, a bill processing apparatus is incorporated into a service providing device, such as a game medium rental machine installed in a game hall, a vending machine or a ticket-vending machine installed in a public space, or the like, which identifies the validity of a bill inserted from a bill insertion slot by a user, and provides various types of products and services in accordance with a value of the bill having been judged as valid.
Recently, it is also seen that a paper sheet or the like (it may also be called a coupon ticket) having an equivalent economic value to that of a bill is issued in a game hall and processed by a bill processing apparatus which handles a regular bill. As such a coupon ticket, what has a bar code printed on a paper sheet (thermal paper) formed in the same size as that of a specific bill (typically, United States dollar bill) is known (i.e., a coupon ticket with a bar code) and it is possible for a user to be provided with equivalent services to those by the bill when the issued coupon ticket with the bar code is inserted, in the same manner as the bill, into the insertion slot of the bill processing apparatus which processes the bill.
Meanwhile, in such a way of using the bill processing apparatus, it is necessary for the abovementioned bill processing apparatus to be configured to be capable of judging the authenticity of the bill as well as such a bar-coded paper sheet. As such a bill processing apparatus, for example, Patent Document 1 discloses a configuration that a sensor device for reading a bill or a bar-coded paper sheet inserted into a bill insertion slot is installed in a bill traveling route.
This sensor device has a magnetic sensor 20 and optical sensors 21 to 23 for reading the bill, and optical sensors 24, 25 for reading a bar-code pattern, and, before or after an object to be identified, which has been inserted from a bill insertion slot, is determined to be a bill containing a magnetic pattern or an optical pattern, the sensor device detects the presence or absence of a bar-code such that the authenticity of the detected bar-code pattern is judged. In this apparatus, however, dedicated sensors (the magnetic sensor 20 and the optical sensors 21 to 23) for reading the bill and dedicated sensors (the optical sensors 24, 25) for reading the bar-code are installed such that the number of components is great.    [Patent Reference 1] Japanese patent No. 3320806